How to get the nickname from the ID?

Is there any function that works on any page where I can get the nickname of the database from the ID?

example:

I have the ID 16 and want to get the nickname in database of who has that ID 16.

Is there any function or command that I can use in a block for that?

Thank you!

For dolphin 7.0.9 and under.

getNickName($id);

For dolphin 7.1.0 and up, and this will be confusing. They changed the getNickName function to return the user display name. This is the name as per the setting in admin for Admin->Settings->Advanced Settings->Profile->Member display-name:

So. To get the Member Display name from the ID use this.

getNickName($id);

To get the nickname as per the nickname field in the database use this.

getUsername($id);

Already got it!

If someone wants to know later, I used:

getUsername ($ID);

We posted at the same time Deano! :)

And his answer is much more complete than mine! Thank you!